Alisa, a skateboarder, is riding down a hill. If Alisa and the skateboard are considered a single object, what forces are acting on her? Check all that apply.

gravity

normal force

friction

Explanation:

A force is refered to as the interaction which when unopposed, will lead to a change in an objects motion. The velocity of an object will be changed when force is applied.

Since Alisa s riding down a hill and she and the skateboard are considered to be a single object, then the forces that are acting on her include gravity, normal force and friction.

b would be the answer